In this paper, a second-order Super Twisting Sliding Mode Control (STSMC) is proposed for a constructed biped robot with 12 degrees of freedom. A biped robot can have many applications, it can be used for research, personal assistance, education, search and rescue, transportation, and more. In this work, the model system of a low-cost designed biped robot is analyzed by using the Denavit-Hartenberg convention to find the joint and link parameters. Inverse kinematics is applied to calculate the joint angles. Then, the trajectories to replicate a squat are generated for every joint and the STSMC is designed and tested. The squat trajectory is introduced in the controller in order to follow it. Finally, the results show that the PID (Proportional, Integrative, and Derivative control) has an average MSE of 0.4704 and the STSMC has an average MSE of 0.0228. The results allow to demonstrate that, for tracking trajectory, control implementation for this low-cost biped robot is possible.
